September 2007 arXiv papers — page 39

A. Meulenberg, B. Jayashree, Ramani, M. C. Radhakrishna

Space-grade Si and GaAs solar cells were irradiated with 15 and 40 MeV lithium ions. Dark-IV analysis (with and without illumination) reveals differences in the effects of such irradiation on the different cell types

Elias P. Gyftopoulos

Interpretations of key concepts, such as uncertainty relations, kinetic energy, value of an observable, probability distributions, the projection or collapse of a wave function postulate, and discrete versus continuous values, that appear in several excellent textbooks on quantum mechanics are reviewed and found not to be consistent with our current understa

Stephen S. Eikenberry, Shannon G. Patel, David M. Rothstein, Ronald Remillard

We report infrared observations of the microquasar GRS 1915+105 using the NICMOS instrument of the Hubble Space Telescope during 9 visits in April-June 2003. During epochs of high X-ray/radio activity near the beginning and end of this period, we find that the $1.87 $\um infrared flux is generally low ($\sim 2$ mJy) and relatively steady. However, during the

M. Aharrouche, J. Colas, L. Di Ciaccio, M. El Kacimi

The construction of the ATLAS electromagnetic liquid argon calorimeter modules is completed and all the modules are assembled and inserted in the cryostats. During the production period four barrel and three endcap modules were exposed to test beams in order to assess their performance, ascertain the production quality and reproducibility, and to scrutinize

Frederic Jugeau

We investigate the mass spectra of scalar and vector glueballs in the so-called bottom-up approach of the AdS/QCD correspondence. The holographic model of QCD includes a static dilaton background field. We study the constraints on the masses coming from perturbing the dilaton field and the geometry of the bulk.

Christian Miebach

We investigate the joint action of two real forms of a semi-simple complex Lie group S by left and right multiplication. After analyzing the orbit structure, we study the CR structure of closed orbits. The main results are an explicit formula of the Levi form of closed orbits and the determination of the Levi cone of generic orbits. Finally, we apply these r

D. Coslovich, C. M. Roland

The manner in which the intermolecular potential u(r) governs structural relaxation in liquids is a long standing problem in condensed matter physics. Herein we show that diffusion coefficients for simulated Lennard-Jones m-6 liquids (8<m<36) in normal and moderately supercooled states are a unique function of the variable rho^g/T, where rho is density and T

Steven S. Gubser, Amos Yarom

As a particle moves through a fluid, it may generate a laminar wake behind it. In the gauge-string duality, we show that such a diffusion wake is created by a heavy quark moving through a thermal plasma and that it has a universal strength when compared to the total drag force exerted on the quark by the plasma. The universality extends over all asymptotical

H. Bercovici, W. S. Li, D. Timotin

We determine the possible eigenvalues of compact selfadjoint operators A,B,C... with the property that A=B+C+... When all these operators are positive, the eigenvalues were known to be subject to certain inequalities which extend Horn&#39;s inequalities from the finite-dimensional case when A=B+C. We find the proper extension of the Horn inequalities and sho

Vincent Minerbe

Asymptotically flat manifolds with Euclidean volume growth are known to be ALE. In this paper, we consider a class of asymptotically flat manifolds with slower volume growth and prove that their asymptotic geometry is that of a fibration over an ALE manifold. In particular, we show that gravitational instantons with cubic volume growth are ALF.

Michele Campisi

When studying the thermodynamic properties of mesoscopic systems the most appropriate microcanonical entropy is the volume entropy, i.e. the logarithm of the volume of phase space enclosed by the hypersurface of constant energy. For systems with broken ergodicity, the volume entropy has discontinuous jumps at values of energy that correspond to separatrix tr

D. Q. Fang, W. Guo, C. W. Ma, K. Wang

The longitudinal momentum distribution (P_{//}) of fragments after one-proton removal from ^{23} Al and reaction cross sections (σ_R) for ^{23,24} Al on carbon target at 74A MeV have been measured. The ^{23,24} Al ions were produced through projectile fragmentation of 135 A MeV ^{28} Si primary beam using RIPS fragment separator at RIKEN. P_{//} is measured

Mechkour Houari

We are interested in the homogenization of elastic-electric coupling equation, with rapidly oscillating coefficients, in periodically perforated piezoelectric body. We justify the two first terms in the usual asymptotic development of the problem solution. For the main convergence results of this paper, we use the notion of {\it two-scale convergence}. A two

Adam D. Helfer

Penrose&#39;s twistorial approach to the definition of angular momentum at null infinity is developed so that angular momenta at different cuts can be meaningfully compared. This is done by showing that the twistor spaces associated with different cuts of scri can be identified as manifolds (but not as vector spaces). The result is a well-defined, Bondi-Metz

Christoph A. Keller

The backreaction of D-branes on closed string moduli is studied in perturbed conformal field theory. To this end we analyse the divergences in the modular integral of the annulus diagram. By the Fischler-Susskind mechanism, these divergences lead to additional terms in the bulk renormalisation group equations. We derive explicit expressions for these backrea

Ansgar Denner

We review the techniques necessary for the calculation of virtual electroweak and soft photonic corrections at the one-loop level. In particular we describe renormalization, calculation of one-loop integrals and evaluation of one-loop Feynman amplitudes. We summarize many explicit results of general relevance. We give the Feynman rules and the explicit form

Shu-Tao Xia, Fang-Wei Fu

Very recently, an operator channel was defined by Koetter and Kschischang when they studied random network coding. They also introduced constant dimension codes and demonstrated that these codes can be employed to correct errors and/or erasures over the operator channel. Constant dimension codes are equivalent to the so-called linear authentication codes int

Michele Cantiello, John P. Blakeslee

We perform a series of numerical experiments to study how the nonlinear metallicity--color relations predicted by different stellar population models affect the color distributions observed in extragalactic globular cluster systems. % We present simulations in the $UBVRIJHK$ bandpasses based on five different sets of simple stellar population (SSP) models. T

Lujun Fang, Zhongzhi Zhang, Shuigeng Zhou, Jihong Guan

We propose a synthetical weights&#39; dynamic mechanism for weighted networks which takes into account the influences of strengths of nodes, weights of links and incoming new vertices. Strength/Weight preferential strategies are used in these weights&#39; dynamic mechanisms, which depict the evolving strategies of many real-world networks. We give insight an

Wei Chao, Shu Luo, Zhi-zhong Xing, Shun Zhou

A natural extension of the standard $SU(2)_{\rm L} \times U(1)_{\rm Y}$ gauge model to accommodate massive neutrinos is to introduce one Higgs triplet and three right-handed Majorana neutrinos, leading to a $6\times 6$ neutrino mass matrix which contains three $3\times 3$ sub-matrices $M_{\rm L}$, $M_{\rm D}$ and $M_{\rm R}$. We show that three light Majoran

Petko D. Proinov

In this paper we study some iterative methods for simultaneous approximation of polynomial zeros. We give new semilocal convergence theorems with error bounds for Ehrlich&#39;s and Nourein&#39;s iterations. Our theorems generalize and improve recent results of Zheng and Huang [J. Comput. Math. 18 (2000), 113--122], Petković and Herceg [J. Comput. Appl. Math.

Carlos C. Rodriguez

All priors are not created equal. There are right and there are wrong priors. That is the main conclusion of this contribution. I use, a cooked-up example designed to create drama, and a typical textbook example to show the pervasiveness of wrong priors in standard statistical practice.

B. J. Park, J. P. Pantina, E. Furst, M. Oettel

The forces between colloidal particles at a decane-water interface, in the presence of low concentrations of a monovalent salt (NaCl) and of the surfactant sodium dodecylsulfate (SDS) in the aqueous subphase, have been studied using laser tweezers. In the absence of electrolyte and surfactant, particle interactions exhibit a long-range repulsion, yet the var

Ch. Kant, T. Rudolf, F. Mayr, S. Krohns

We report on phonon properties and electronic transitions in CaCu3Ti4O12, a material which reveals a colossal dielectric constant at room temperature without any ferroelectric transition. The results of far- and mid-infrared measurements are compared to those obtained by broadband dielectric and millimeter-wave spectroscopy on the same single crystal. The un

Didier Henrion

In the complex plane, the frequency response of a univariate polynomial is the set of values taken by the polynomial when evaluated along the imaginary axis. This is an algebraic curve partitioning the plane into several connected components. In this note it is shown that the component including the origin is exactly representable by a linear matrix inequali

Karl-Hermann Neeb

We describe natural abelian extensions of the Lie algebra $\aut(P)$ of infinitesimal automorphisms of a principal bundle over a compact manifold $M$ and discuss their integrability to corresponding Lie group extensions. Already the case of a trivial bundle $P = M \times K$ is quite interesting. In this case, we show that essentially all central extensions of

Karl-Hermann Neeb

A host algebra of a topological group G is a C^*-algebra whose representations are in one-to-one correspondence with certain continuous unitary representations of G. In this paper we present an approach to host algebras for infinite dimensional Lie groups which is based on complex involutive semigroups. Any locally bounded absolute value αon such a semigroup

B. Dierckx, M. Fannes, M. Pogorzelska

This paper and the results therein are geared towards building a basic toolbox for calculations in quantum information theory of quasi-free fermionic systems. Various entropy and relative entropy measures are discussed and the calculation of these reduced to evaluating functions on the one-particle component of quasi-free states. The set of quasi-free affine

T. Giannini, D. Lorenzetti, M. De Luca, B. Nisini

A new, unbiased Spitzer-MIPS imaging survey (~1.8 square degs) of the young stellar content of the Vela Molecular Cloud-D is presented. The survey is complete down to 5mJy and 250mJy at 24micron (mu) and 70mu, respectively. 849 sources are detected at 24mu and 52 of them also have a 70mu counterpart. The VMR-D region is one that we have already partially map

Petko D. Proinov

In this paper we present a new semilocal convergence theorem from data at one point for the Weierstrass iterative method for the simultaneous computation of polynomial zeros. The main result generalizes and improves all previous ones in this area.

Vicente Garzo

Transport coefficients associated with the mass flux of a binary mixture of Maxwell molecules under uniform shear flow are exactly determined from the Boltzmann kinetic equation. A normal solution is obtained via a Chapman--Enskog-like expansion around a local shear flow distribution that retains all the hydrodynamics orders in the shear rate. In the first o

Ralf Gerkmann, Mao Sheng, Kang Zuo

The purpose of these notes is to provide the details of the Jacobian ring computations carried out in [1], based on the computer algebra system Magma [2].

B. F. Kostenko, M. Z. Yuriev

A simple explanation of the fact that light magnetic monopoles have not been observed at accelerator experiments is given. It is based on a possibility of violation of C invariance in the electromagnetic interactions. Because of the difficulty of monopole registration, two interconnected problems arise: to formulate a theory describing monopole production (i

Ralf Gerkmann, Sheng Mao, Kang Zuo

We prove that the moduli space of Calabi-Yau 3-folds coming from eight planes of $P^3$ in general positions is not modular. In fact we show the stronger statement that the Zariski closure of the monodromy group is actually the whole $Sp(20,R)$. We construct an interesting submoduli, which we call \emph{hyperelliptic locus}, over which the weight 3 $Q$-Hodge

Thomas Cokelaer

Matched filtering is used to search for gravitational waves emitted by inspiralling compact binaries in data from ground-based interferometers. One of the key aspects of the detection process is the deployment of a set of templates, also called a template bank, to cover the astrophysically interesting region of the parameter space. In a companion paper, we d

Grigory Mikhalkin

These condensed notes treat some basic notions in Tropical Geometry (varieties, cycles, modifications, equivalence). These topics are to be extended, illustrated and included to the upcoming book project http://www.math.toronto.edu/mikha/book.pdf .

A. R. Yeates, D. Nandy, D. H. Mackay

The predictability, or lack thereof, of the solar cycle is governed by numerous separate physical processes that act in unison in the interior of the Sun. Magnetic flux transport and the finite time delay it introduces, specifically in the so-called Babcock-Leighton models of the solar cycle with spatially segregated source regions for the alpha and omega ef

C. Lane, G. Hallinan, R. T. Zavala, R. F. Butler

We find periodic I-band variability in two ultracool dwarfs, TVLM 513-46546 and 2MASS J00361617+1821104, on either side of the M/L dwarf boundary. Both of these targets are short-period radio transients, with the detected I-band periods matching those found at radio wavelengths (P=1.96 hr for TVLM 513-46546, and P=3 hr for 2MASS J00361617+1821104). We attrib

O. V. Barabash, H. P. Pyatkovska

We study the weak-field limit of the conformal Weyl gravity suggested by Mannheim as an alternative to Einstein&#39;s General Relativity modeling both dark matter and dark energy. We solve the field equations of the theory in the weak-field approximation for an arbitrary spherically symmetric static distribution of matter in the physical gauge with constant

Alberto C. Balfagon

We show a tensorial-computational way to find out conditions that must fulfil an m-rank tensor in arbitrary dimension in order to be algebraically the energy-momentum tensor of some field. We apply in this paper our method to three 2-rank tensors: electromagnetic, mass less scalar field and perfect fluid tensors. Finally we apply the Rainich theory to some e

Steven P. Lalley

In the simple mean-field SIS and SIR epidemic models, infection is transmitted from infectious to susceptible members of a finite population by independent $p-$coin tosses. Spatial variants of these models are proposed, in which finite populations of size $N$ are situated at the sites of a lattice and infectious contacts are limited to individuals at neighbo

D. N. Argyriou, O. Prokhnenko, K. Kiefer, C. J. Milne

We have utilized neutron powder diffraction to probe the crystal structure of layered Na$_{x}$CoO$_{2}$ near the half doping composition of $x=$0.46 over the temperature range of 2 to 600K. Our measurements show evidence of a dynamic transition in the motion of Na-ions at 300K which coincides with the onset of a near zero thermal expansion in the in-plane la

H. K. Eriksen, C. Dickinson, J. B. Jewell, A. J. Banday

Using a Gibbs sampling algorithm for joint CMB estimation and component separation, we compute the large-scale CMB and foreground posteriors of the 3-yr WMAP temperature data. Our parametric data model includes the cosmological CMB signal and instrumental noise, a single power law foreground component with free amplitude and spectral index for each pixel, a

F. A. Majeed

Electron scattering form factors from $^{12}$C have been studied in the framework of the particle-hole shell model. Higher configurations are taken into account by allowing particle-hole excitations from the 1$s$ and 1$p$ shells core orbits up to the 1$f-2p$ shell. The inclusion of the higher configurations modifies the form factors markedly and describes th

M. De Becker, G. Rauw, J. M. Pittard, R. Blomme

An increasing number of early-type (O and Wolf-Rayet) colliding wind binaries (CWBs) is known to accelerate particles up to relativistic energies. In this context, non-thermal emission processes such as inverse Compton (IC) scattering are expected to produce a high energy spectrum, in addition to the strong thermal emission from the shock-heated plasma. SIMB

Mike Bisset, Nick Kersting, Jun Li

Heretofore neglected decay modes of heavy MSSM Higgs bosons into a variety of neutralino pairs may push the LHC discovery reach for these crucial elements of an extended Higgs sector to nearly the TeV-scale -- if sparticle-sector MSSM input parameters are favorable. This is well into the so-called decoupling region, including moderate to low tan(beta) values

Hans-Ulrich Martyn

A study is presented illustrating the excellent potential of future International Linear Collider (ILC) experiments to detect metastable staus $\stau$, measure precisely their mass and lifetime, and to determine the mass of the gravitino $\sG$ from the decay $\stau\toτ\sG$, thus providing direct access to the gravitational coupling, respectively Planck scale

Steffen Schumann, Frank Krauss

In this publication the implementation of a new parton shower model based on the Catani-Seymour dipole factorisation, as first suggested by Z. Nagy and D. E. Soper, is discussed. First results obtained with the new algorithm are compared with experimental data.

Roland Bouffanais, Vincent Keller, Ralf Gruber, Michel O. Deville

In this paper, a comprehensive performance review of a MPI-based high-order spectral and mortar element method C++ toolbox is presented. The focus is put on the performance evaluation of several aspects with a particular emphasis on the parallel efficiency. The performance evaluation is analyzed and compared to predictions given by a heuristic model, the so-

Florent Krzakala, Jorge Kurchan

We describe an effective landscape introduced in [1] for the analysis of Constraint Satisfaction problems, such as Sphere Packing, K-SAT and Graph Coloring. This geometric construction reexpresses these problems in the more familiar terms of optimization in rugged energy landscapes. In particular, it allows one to understand the puzzling fact that unsophisti

Pedro A. F. Cruz, Delfim F. M. Torres

Evolution Strategies are inspired in biology and part of a larger research field known as Evolutionary Algorithms. Those strategies perform a random search in the space of admissible functions, aiming to optimize some given objective function. We show that simple evolution strategies are a useful tool in optimal control, permitting to obtain, in an efficient

J. Dugué, G. Dennis, M. Jeppesen, M. T. Johnsson

We report the experimental realisation of a multibeam atom laser. A single continuous atom laser is outcoupled from a Bose-Einstein condensate (BEC) via an optical Raman transition. The atom laser is subsequently split into up to five atomic beams with slightly different momenta, resulting in multiple, nearly co-propagating, coherent beams which could be of

G. Z. Krumova, E. Tomasi-Gustafsson, A. N. Antonov

The charge form factor of ${}^6$Li nucleus is considered on the basis of its cluster structure. The charge density of ${}^6$Li is presented as a superposition of two terms. One of them is a folded density and the second one is a sum of ${}^4$He and the deuteron densities. Using the available experimental data for ${}^4$He and deuteron charge form factors, a

Leonid A. Chernozatonskii, Pavel B. Sorokin, Jochen W. Bruning

It is shown that lines of adsorbed hydrogen pair atoms divide the graphene sheet into strips and form hydrogen-based superlattice structures (2HG-SL). We show that the forming of 2HG-SL drastically changes the electronic properties of graphene from semimetal to semiconductor. The electronic spectra of &#34;zigzag&#34; (n,0) 2HG-SL is similar to that of (n,0)

Aad W. van der Vaart, Jon A. Wellner

We consider the convergence of empirical processes indexed by functions that depend on an estimated parameter $η$ and give several alternative conditions under which the ``estimated parameter&#39;&#39; $η_n$ can be replaced by its natural limit $η_0$ uniformly in some other indexing set $Θ$. In particular we reconsider some examples treated by Ghoudi and Rem

Anna Salvati, Sandra Ristori, Daniela Pietrangeli, Julian Oberdisse

The synthesis, characterization and liposome insertion of a novel magnesium(II) carboranyl-porphyrazine, i.e. [2,3,7,8,12,13,17,18-octakis- (1,2-dicarba-closo-dodecaboranyl)-hexylthio-5,10,15,20- porphyrazine]magnesium(II) complex, MgHECSPz, is described. MgHECSPz was designed to improve the potentiality in multiple approach anticancer therapy. Liposomal for

Y. Shioya, Y. Taniguchi, S. S. Sasaki, T. Nagao

To derive a new H$α$ luminosity function and to understand the clustering properties of star-forming galaxies at $z \approx 0.24$, we have made a narrow-band imaging survey for H$α$ emitting galaxies in the HST COSMOS 2 square degree field. We used the narrow-band filter NB816 ($λ_c = 8150$ Å, $Δλ= 120$ Å) and sampled H$α$ emitters with $EW_{\rm obs}(\rm Hα+

M. N. Achasov, K. I. Beloborodov, A. V. Berdyugin, A. G. Bogdanchikov

In the experiment with the SND detector at the VEPP-2M $e^+e^-$ collider measuring the $e^+e^-\to ηγ$ cross section in the energy range $0.6<\sqrt{s}<1.38 \mathrm{GeV}$ the reanalysis of data is performed. The goal is to improve the accuracy of the previous results by analysing ambiguities in the approximation of energy dependence of the $e^+e^-\to ηγ$ cross

J. J. Chapman, B. G. Norton, E. W. Streed, D. Kielpinski

The focusing properties of three aspheric lenses with numerical aperture (NA) between 0.53 and 0.68 were directly measured using an interferometrically referenced scanning knife-edge beam profiler with sub-micron resolution. The results obtained for two of the three lenses tested were in agreement with paraxial gaussian beam theory. It was also found that th

Peter Schneider, Xinzhong Er

In weak gravitational lensing, the image distortion caused by shear measures the projected tidal gravitational field of the deflecting mass distribution. To lowest order, the shear is proportional to the mean image ellipticity. If the image sizes are not small compared to the scale over which the shear varies, higher-order distortions occur, called flexion.

Shoichi Sasaki, Takeshi Yamazaki

We discuss signatures of bound-state formation in finite volume via the Luscher finite size method. Assuming that the phase-shift formula in this method inherits all aspects of the quantum scattering theory, we may expect that the bound-state formation induces the sign of the scattering length to be changed. If it were true, this fact provides us a distincti

T. Morita, T. Zh. Esirkepov, S. V. Bulanov, J. Koga

The laser-driven acceleration of high quality proton beams from a double-layer target, comprised of a high-Z ion layer and a thin disk of hydrogen, is investigated with three-dimensional particle-in-cell simulations in the case of oblique incidence of a laser pulse. It is shown that the proton beam energy reaches its maximum at a certain incidence angle of t

Dimitrios I. Dais

Toric log Del Pezzo surfaces with Picard number 1 have been completely classified whenever their index is $\le 2$: In this paper we extend the classification for those having index 3: We prove that, up to isomorphism, there are exactly 18 surfaces of this kind.

V. Prudnikov, P. Prudnikov, B. Zheng, S. Dorofeev

Monte Carlo simulations of the short-time dynamic behavior are reported for three-dimensional Ising and XY models with long-range correlated disorder at criticality, in the case corresponding to linear defects. The static and dynamic critical exponents are determined for systems starting separately from ordered and disordered initial states. The obtained val

P. N. Segre

We use particle image velocimetry to measure the sedimentation dynamics of a semi-dilute suspension of non-Brownian spheres at Reynolds numbers, $0.001\le Re\le 2.3$, extending from the Stokes to the moderately inertial regime. We find that the onset of inertial corrections to Stokes sedimentation occurs when the inertial screening length $l=a/Re$ becomes si

A. Awasthi, S. C. Hendy, P. Zoontjens, S. A. Brown

We conduct molecular dynamics simulations of the collision of atomic clusters with a weakly-attractive surface. We focus on an intermediate regime, between soft-landing and fragmentation, where the cluster undergoes deformation on impact but remains largely intact, and will either adhere to the surface (and possibly slide), or be reflected. We find that the

O. I. Shro

This article is presented new method of description information systems in abstract 4-dimensional pseudo-Euclidean information space (4-DPIES) with using special relativity (SR) methods. This purpose core postulates of existence 4-DPIES are formulated. The theorem setting existence criteria of the invariant velocity of the information transference is formula

Zhiping Xu

The mechanical response of graphene nano-ribbon under tensile loading has been investigated using atomistic simulation. Lattice symmetry dependence of elastic properties are found, which fits prediction from Cauchy-Born rule well. Concurrent brittle and ductile behaviors are observed in the failure process at elastic limit, which dominates at low and high te

Hideyuki Kamaya

Context.Recent study of SDSS J1257+3419 has revealed that this stellar system is either a faint and small dwarf galaxy or a faint and widely extended globular cluster (see also arXiv:0709.0327 [astro-ph]). Aims.In this short note, the author suggests that this system is one of the smallest dwarf spheroidals (dSphs) in the Milky Way. Methods.We re-examine som

Yanir A. Rubinstein

In this article and in its sequel we propose the study of certain discretizations of geometric evolution equations as an approach to the study of the existence problem of some elliptic partial differential equations of a geometric nature as well as a means to obtain interesting dynamics on certain infinite-dimensional spaces. We illustrate the fruitfulness o

Zhiping Xu, Quanshui Zheng, Qing Jiang, Chi-Chiu Ma

We report a novel phenomenon in carbon nanotube (CNT) based devices, the transphonon effects, which resemble the transonic effects in aerodynamics. It is caused by dissipative resonance of nanotube phonons similar to the radial breathing mode, and subsequent drastic surge of the dragging force on the sliding tube, and multiple phonon barriers are encountered

M. Rab, J. H. Cole, N. G. Parker, A. D. Greentree

Classically it is impossible to have transport without transit, i.e., if the points one, two and three lie sequentially along a path then an object moving from one to three must, at some point in time, be located at two. However, for a quantum particle in a three-well system it is possible to transport the particle between wells one and three such that the p

Lewis C. Roberts,, Doyle T. Hall, John V. Lambert, John L. Africano

In August 2002, the near-Earth asteroid 2002 NY40, made its closest approach to the Earth. This provided an opportunity to study a near-Earth asteroid with a variety of instruments. Several of the telescopes at the Maui Space Surveillance System were trained at the asteroid and collected adaptive optics images, photometry and spectroscopy. Analysis of the im

Wayne A. Barkhouse, H. K. C. Yee, Omar López-Cruz

We present the results from a survey of 57 low-redshift Abell galaxy clusters to study the radial dependence of the luminosity function (LF). The dynamical radius of each cluster, r200, was estimated from the photometric measurement of cluster richness, Bgc. The shape of the LFs are found to correlate with radius such that the faint-end slope, alpha, is gene

Gonzalo Comas

We give a characterization of the rational normal curve in terms of the rank function associated to a curve.

Rouven Essig, Jean-François Fortin

The regions in the Minimal Supersymmetric Standard Model with the minimal amount of fine-tuning of electroweak symmetry breaking are presented for general messenger scale. No a priori relations among the soft supersymmetry breaking parameters are assumed and fine-tuning is minimized with respect to all the important parameters which affect electroweak symmet

Sergey Gubin

A polynomial time algorithm which detects all paths and cycles of all lengths in form of vertex pairs (start, finish).

Hitoshi Nishino, Subhash Rajpoot

It has been recently shown that Nambu-Goto action can be re-expressed in terms of Cayley&#39;s hyperdeterminant with the manifest SL(2,R) X SL(2,R) X SL(2,R) symmetry. In the present paper, we show that the same feature is shared by Green-Schwarz sigma-model for N=2 superstring whose target space-time is D=2+2. When its zweibein field is eliminated from the

Carl W. Akerlof, Heather F. Swan

By using recent publicly available observational data obtained in conjunction with the NASA Swift gamma-ray burst mission and a novel data analysis technique, we have been able to make some rough estimates of the GRB afterglow apparent optical brightness distribution function. The results suggest that 71% of all burst afterglows have optical magnitudes with

Augustin Banyaga, David Hurtubise

Let $f:M \to \mathbb{R}$ be a Morse-Bott function on a compact smooth finite dimensional manifold $M$. The polynomial Morse inequalities and an explicit perturbation of $f$ defined using Morse functions $f_j$ on the critical submanifolds $C_j$ of $f$ show immediately that $MB_t(f) = P_t(M) + (1+t)R(t)$, where $MB_t(f)$ is the Morse-Bott polynomial of $f$ and

Daniel Almehed, Friedrich Doenau, Stefan Frauendorf

Chiral vibrations are studied with the RPA plus self-consistent tilted axis cranking formalism in the A=135 region. In this method chiral vibrations appear as a precursor to the static chiral regime. The properties of the RPA phonons are discussed and compared to experimental data. We discuss the limits the chiral region and the transition to the non harmoni

Dimitris Stamatellos, Anthony P. Whitworth

Gravitational fragmentation has been proposed as a mechanism for the formation of giant planets in close orbits around solar-type stars. However, it is debatable whether this mechanism can function in the inner regions (R<40 AU) of real discs. We use a newly developed method for treating the energy equation and the equation of state, which accounts for radia

Rodrigo G. Pereira, Steven R. White, Ian Affleck

Exact formulas for the singularities of the dynamical structure factor, S^{zz}(q,omega), of the S=1/2 xxz spin chain at all q and any anisotropy and magnetic field in the critical regime are derived, expressing the exponents in terms of the phase shifts which are known exactly from the Bethe ansatz solution. We also study the long time asymptotics of the sel

Ryuichi Kurosawa, Daniel Proga

We present three-dimensional (3-D) hydrodynamical simulations of gas flows in the vicinity of an active galactic nucleus (AGN) powered by a precessing accretion disk. We consider the effects of the radiation force from such a disk on its environment on a relatively large scale (up to ~10 pc. We implicitly include the precessing disk by forcing the disk radia

Yanou Cui, Stephen P. Martin, David E. Morrissey, James D. Wells

Flat directions are a generic feature of the scalar potential in supersymmetric gauge field theories. They can arise, for example, from D-terms associated with an extra abelian gauge symmetry. Even when supersymmetry is broken softly, there often remain directions in the scalar field space along which the potential is almost flat. Upon breaking a gauge symme

Yu-Wen Lee

We study the phase diagram of two weakly coupled one-dimensional dipolar boson chains at half-odd-integer fillings. We find that the system contains a rich phase diagram. Four different phases are found. They are the Mott insulators, the single-particle resonant superfluid, the paired superfluid, and the bond- or inter-chain density waves. Moreover, the Mott

Hitoshi Murayama, Yasunori Nomura, David Poland

There is a growing appreciation that hidden sector dynamics may affect the supersymmetry breaking parameters in the visible sector (supersymmetric standard model), especially when the dynamics is strong and superconformal. We point out that there are effects that have not been previously discussed in the literature. For example, the gaugino masses are suppre

Floyd W. Stecker

Ongoing deep surveys of galaxy luminosity functions, spectral energy distributions and backwards evolution models of star formation rates can be used to calculate the past history of intergalactic photon densities and, from them, the present and past optical depth of the universe. This procedure can be reversed by looking for sharp cutoffs in the spectra of

Hovhannes R. Grigoryan

We study the effects of dimension six terms on the predictions of the holographic model for the vector meson form factors and determine the corrections to the electric radius, the magnetic and the quadrupole moments of the rho-meson. We show that the only dimension six terms which contribute nontrivially to the vector meson form factors are X^2F^2 and F^3. I

Oded Hod, Veronica Barone, Gustavo E. Scuseria

A comprehensive first-principles theoretical study of the electronic properties and half-metallic nature of finite rectangular graphene nanoribbons is presented. We identify the bisanthrene isomer of the C28H14 molecule to be the smallest polycyclic aromatic hydrocarbon to present a spin polarized ground state. Even at this quantum dot level, the spins are p

G. G. Nyambuya

I propose three new curved spacetime versions of the Dirac Equation. These equations have been developed mainly to try and account in a natural way for the observed anomalous gyromagnetic ratio of Fermions. The derived equations suggest that particles including the Electron which is thought to be a point particle do have a finite spatial size which is the re

Ivan Booth

This article translates some recent results on quasilocal horizons into the language of $(3+1)$ general relativity so as to make them more useful to numerical relativists. In particular quantities are described which characterize how quickly an apparent horizon is evolving and how close it is to either equilibrium or extremality.

O. Pages, A. V. Postnikov, M. Kassem, A. Chafi

We demonstrate how to overcome serious problems in understanding and classification of vibration spectra in semiconductor alloys, following from traditional use of the virtual crystal approximation (VCA). We show that such different systems as InGaAs (1-bond->1-mode behavior), InGaP (modified 2-mode) and ZnTeSe (2-bond->1-mode) obey in fact the same phonon m

Malgorzata J. Krawczyk, Krzysztof Kulakowski

A system of differential equations is proposed designed as to identify communities in weighted networks. The input is a symmetric connectivity matrix $A_{ij}$. A priori information on the number of communities is not needed. To verify the dynamics, we prepared sets of separate, fully connected clusters. In this case, the matrix $A$ has a block structure of z

J. R. Petta, J. M. Taylor, A. C. Johnson, A. Yacoby

We polarize nuclear spins in a GaAs double quantum dot by controlling two-electron spin states near the anti-crossing of the singlet (S) and m_S=+1 triplet (T+) using pulsed gates. An initialized S state is cyclically brought into resonance with the T+ state, where hyperfine fields drive rapid rotations between S and T+, &#39;flipping&#39; an electron spin a

Analabha Roy, Linda E. Reichl

We investigate the quantum behavior of a mesoscopic two-boson system produced by number-squeezing ultracold gases of alkali metal atoms. The quantum Poincare maps of the wavefunctions are affected by chaos in those regions of the phase space where the classical dynamics produces features that are comparable to hbar. We also investigate the possibility for qu

Stuart Armstrong

This note aims to demonstrate that every parabolic geometry has a naturally defined per-Courant algebroïd structure. This structure is a Courant algebroïd if and only if the the curvature $κ$ of the Cartan connection vanishes. In all other cases, if the parabolic geometry is regular, there does not exist a natural universal expression for a Courant bracket.

S. Cojocaru

It is shown that the Green&#39;s function on a finite lattice in arbitrary space dimension can be obtained from that of an infinite lattice by means of translation operator. Explicit examples are given for one- and two-dimensional lattices.

N. R. Tanvir, A. J. Levan

The properties of their hosts provide important clues to the progenitors of different classes of gamma-ray bursts (GRBs). The hosts themselves also constitute a sample of high-redshift star-forming galaxies which, unlike most other methods, is not selected on the luminosities of the galaxies themselves. We discuss what we have learnt from and about GRB host

Ioannis Rousochatzakis

We present a microscopic theory for the phonon-driven decay of the magnetization fluctuations in a wide class of nanomagnets where the dominant energy is set by isotropic exchange and/or uniaxial anisotropy. Based on the Zwanzig-Mori projection formalism, the theory reveals that the magnetization fluctuations are governed by a single decay rate $ω_c$, which